A “high-risk” sex offender with convictions for rape and kidnapping is considered a person of interest in the death of federal investigator Sandra Coke, authorities said.

Investigators believe Randy Alana, 56, was with Coke the evening of Aug. 4, the day she disappeared after leaving her home to pick up a prescription for her daughter.

Coke’s car — a convertible Mini Cooper — was found a few days later about two miles away. The body of the 50-year-old was found Friday outside a park in Vacaville.

In a brief news conference Tuesday, police spokeswoman Johnna Watson said Alana was a "person of interest" in the case but was not a suspect.

"We are extremely limited in the information we can share about this investigation," Watson said.

Coke was a capital case investigator for the federal public defender's office in Sacramento.

Her family and friends had gathered together in the Bay Area after Coke went missing and announced a $100,000 reward for anyone with information that would lead police to her.

Relatives described Coke as a wonderful friend, mother and sister "dedicated to caring for others in her professional and personal life."

A search for Coke's body began Thursday evening at the Solano County Fairgrounds near Six Flags Discovery Kingdom, based on information received from Oakland investigators.

At least two dogs and more than 70 searchers from multiple agencies combed the area into the night and resumed again the next morning.

On Friday afternoon, Oakland investigators received information that moved the search to the Vacaville park, where Coke's body was discovered.

Alana is listed on California's Megan's Law database as a "high-risk" sex offender with convictions for rape, rape in concert with force or violence, kidnapping with intent to commit a sex offense and oral copulation.

The database noted that Alana had been in violation of registration requirements since June 11.

He was assigned a GPS monitoring device after his last release from custody on a second-degree burglary conviction, and a second database indicates a warrant was issued for his arrest Aug. 6 for failure "to participate" in the monitoring program.

An alarm sounds when a GPS device is tampered with. It remained unclear Tuesday when Alana had tampered with his device and what parole officers knew about his whereabouts.

A spokesman for the state Department of Corrections and Rehabilitation said Oakland police had requested that no information on Alana be shared at this time. "It is our standing policy that we check with an investigating agency when asked," he said. "They have asked us not to."

Alana and Coke dated briefly two decades ago, and he recently contacted her.

[For the record, 2 p.m., Aug. 14: An earlier version of this post incorrectly inferred that Coke and Alana were seen together before she left her home on Aug. 4. Authorities believe Alana and Coke were together later in the evening.]